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/*
* rev implementation for busybox
*
* Copyright (C) 2010 Marek Polacek <mmpolacek@gmail.com>
*
* Licensed under GPLv2, see file LICENSE in this source tree.
*/
//config:config REV
//config: bool "rev (4.4 kb)"
//config: default y
//config: help
//config: Reverse lines of a file or files.
//applet:IF_REV(APPLET(rev, BB_DIR_BIN, BB_SUID_DROP))
//kbuild:lib-$(CONFIG_REV) += rev.o
//usage:#define rev_trivial_usage
//usage: "[FILE]..."
//usage:#define rev_full_usage "\n\n"
//usage: "Reverse lines of FILE"
#include "libbb.h"
#include "unicode.h"
#undef CHAR_T
#if ENABLE_UNICODE_SUPPORT
# define CHAR_T wchar_t
#else
# define CHAR_T char
#endif
/* In-place invert */
static void strrev(CHAR_T *s, int len)
{
int i;
if (len != 0) {
len--;
if (len != 0 && s[len] == '\n')
len--;
}
for (i = 0; i < len; i++, len--) {
CHAR_T c = s[i];
s[i] = s[len];
s[len] = c;
}
}
int rev_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int rev_main(int argc UNUSED_PARAM, char **argv)
{
int retval;
size_t bufsize;
char *buf;
init_unicode();
getopt32(argv, "");
argv += optind;
if (!argv[0])
argv = (char **)&bb_argv_dash;
retval = EXIT_SUCCESS;
bufsize = 256;
buf = xmalloc(bufsize);
do {
size_t pos;
FILE *fp;
fp = fopen_or_warn_stdin(*argv++);
if (!fp) {
retval = EXIT_FAILURE;
continue;
}
pos = 0;
while (1) {
/* Read one line */
buf[bufsize - 1] = 1; /* not 0 */
if (!fgets(buf + pos, bufsize - pos, fp))
break; /* EOF/error */
if (buf[bufsize - 1] == '\0' /* fgets filled entire buffer */
&& buf[bufsize - 2] != '\n' /* and did not read '\n' */
&& !feof(fp)
) {
/* Line is too long, extend buffer */
pos = bufsize - 1;
bufsize += 64 + bufsize / 8;
buf = xrealloc(buf, bufsize);
continue;
}
/* Process and print it */
#if ENABLE_UNICODE_SUPPORT
{
wchar_t *tmp = xmalloc(bufsize * sizeof(wchar_t));
/* Convert to wchar_t (might error out!) */
int len = mbstowcs(tmp, buf, bufsize);
if (len >= 0) {
strrev(tmp, len);
/* Convert back to char */
wcstombs(buf, tmp, bufsize);
}
free(tmp);
}
#else
strrev(buf, strlen(buf));
#endif
fputs_stdout(buf);
}
fclose(fp);
} while (*argv);
if (ENABLE_FEATURE_CLEAN_UP)
free(buf);
fflush_stdout_and_exit(retval);
}
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